How do you choose to use coins in Hay Day?

The question sounds like I don’t know how to use coins in the game but I didn’t know how else to phrase it. One thing I like to do is keep my coins above a certain amount so I can make any emergency purchases of expensive things (expansion materials type things). What are your minimums at whatever level you are at?

Similarly, I only use diamonds for permanent purchases (more slots in machines, more spots in my roadside shop) and never to make soemthing go faster or in products. Do you also save diamonds (not use them to make items like diamond rings/gracious bouquets) or do you use them up whenever you get them? I’m sure this says something about my personality type lol